Dry Lessons from Drought

Published on 11th April 2006

Basil Somlahlo’s words in “Drought” capture the predicament that befell the Horn of Africa early this year: The burning skies were steel; the scorched ground was dry. The children reeled and fainted as humans and cattle died. The God who lives on high was no Father to his people, for permitting such misery.

Indeed, that was the situation. Families in Ikutha (Kitui District) resorted to eating roots and baobab fruits. Ikalaasa Farmers Poverty Alleviators (Machakos District), not wanting history to repeat itself resorted to digging a 5ft deep dam on land donated by a group member, Redempta Maingi.

“We hope that when God remembers us, rain waters descending from the raised part of the land shall fill this dam,” explained Mbindyo, the group chairperson, wiping the sweat that had formed rivulets all over his body.

“This water will in turn be used to irrigate the surrounding farm, where we intend to grow all types of food,” added panting Damiana Mule, the group Treasurer, shoving the soil aside. The number of times it rains in this region can be counted by a nursery school pupil.

That was then. The status quo now is best captured in Pius Oleghe’s poem A Sudden Storm:

The wind howls the trees sway

The loose housetop sheets clatter and clang

The open window shuts with a bang

And the sky makes night of day

Helter skelter the parents run

Pressed with a thousand minor cares

Hey you there! Pack the house wares!

And where on earth is my son?

The Friday 7 April edition of The Citizen, a Dar es alaam based paper carried a picture of a driver yelling for help as his truck sank in water after a heavy downpour in the city. InKenya, it is no different. It is a nightmare to be trapped in the rains on the city streets. One has to contend with wading in 2ft deep water to board a bus. Floods have displaced families. Lives have been lost. The blessing that was longed for has suddenly turned into a curse!

As I see this misguided water wreck havoc in many parts of Africa, I wonder- can’t it be harnessed for use in lean times? Won’t we be complaining about drought next year? Shall we not seek donor funding to fight hunger next year?

Since ancient times, notes Prof. Dr. Dieter Prinz, farmers and herders in dry areas of the tropics and subtropics have attempted to ‘harvest’ water to secure or increase agricultural production. A wide range of indigenous irrigation techniques can be found in areas between 100 and 1500 mm annual precipitation and with population densities varying from 10- 500 persons per square kilometer. These traditional methods played a much greater role in the past and were the backbone of ancient civilizations in arid and semi-arid areas.

In the Middle East, archaeological evidence of water harvesting structures appears in Jordan, Israel, Palestine, Syria, Iraq, the Negev and the Arabian Peninsula (mainly the Yemen); the oldest being believed to have been constructed over 9,000 years ago. In Baluchistan, Pakistan, two water-harvesting techniques have a long tradition: the "Khuskaba" macro catchment system and the "Sailaba" system, which utilizes floods. In India a great variety of rain water-harvesting techniques developed over the last 2,000 years. In many areas, the "tank" system is traditionally the backbone of agricultural production. Ahars are important in Bihar region; unlike tanks, the beds are not dug out. Out of the 46 million hectares under irrigation in India, about 6 million hectares are irrigated from "sources other than government canals, wells and tubewells," mainly various forms of water harvesting (Agarwal & Narain 1997, UNEP 1983, Sengupta 1993, Pacey and Cullis 1986).

In North Africa, water harvesting has a long tradition and is still used extensively in Morocco, Tunisia and to a lesser extent in Algeria. Traditional techniques of water harvesting have been reported from many regions of Sub- Saharan Africa like the "Caag" and the "Gawan" systems in Somalia; various types of "Hafirs" in Sudan and the ‘Zay’ system in West Africa.

Rainwater harvesting is a technology used for collecting and storing rainwater from rooftops, the land surface or rock catchments using simple techniques such as jars and pots as well as more complex techniques such as underground check dams. Commonly used systems are constructed of three principal components; namely, the catchment area, the collection device, and the conveyance system.

The most basic form of this technology is the rooftop catchment. Here, rainwater is collected in simple vessels at the edge of the roof. Variations on this basic approach include collection of rainwater in gutters which drain to the collection vessel through down-pipes constructed for this purpose, and/or the diversion of rainwater from the gutters to containers for settling particulates before being conveyed to the storage container for domestic use. As the rooftop is the main catchment area, the amount and quality of rainwater collected depends on the area and type of roofing material. Reasonably pure rainwater can be collected from roofs constructed with galvanized corrugated iron, aluminium or asbestos cement sheets, tiles and slates, although thatched roofs tied with bamboo gutters and laid in proper slopes can produce almost the same amount of runoff less expensively. However, the bamboo roofs are least suitable because of possible health hazards. Similarly, roofs with metallic paint or other coatings are not recommended as they may impart tastes or colour to the collected water. Roof catchments should also be cleaned regularly to remove dust, leaves and bird droppings so as to maintain the quality of the product water.

Rainwater harvesting using ground or land surface catchment involves improving runoff capacity of the land surface through various techniques including collection of runoff with drain pipes and storage of collected water. Compared to rooftop catchment techniques, ground catchment techniques provide more opportunity for collecting water from a larger surface area. By retaining the flows (including flood flows) of small creeks and streams in small storage reservoirs (on surface or underground) created by low cost (e.g., earthen) dams, this technology can meet water demands during dry periods. There is a possibility of high rates of water loss due to infiltration into the ground, and, because of the often marginal quality of the water collected, this technique is mainly suitable for storing water for agricultural purposes. Various techniques available for increasing the runoff within ground catchment areas involve: clearing or altering vegetation cover; increasing the land slope with artificial ground cover; and reducing soil permeability by the soil compaction and application of chemicals.

Rainwater harvesting technologies are simple to install and operate. Local people can be easily trained to implement such technologies, and construction materials are also readily available. It provides water at the point of consumption, and family members have full control of their own systems, which greatly reduces operation and maintenance problems. Running costs, also, are almost negligible (MaESTro Database, UNEP-IETC).

Professor Jana Olivier of the University of South Africa's Department of Anthropology, Archaeology, Geography and Environmental Studies, explains that the idea of harnessing fog as a source of drinking water has been studied for decades.

For years, the remote fishing village of Chungungo relied solely on trucked-in water. In 1987 it was transformed by the installation of a fog collecting system. With a dependable and affordable water supply, not only did the growing population have domestic water, they were also able to cultivate commercial crops and plant trees.

The technology involves massive vertical shade nets being erected in high-lying areas close to water-short communities. As fog blows through these structures, tiny water droplets are deposited onto the net. As the droplets become larger, they run down the net into gutters attached at the bottom. From there, water is channeled into reservoirs, and then to individual homes.

In Chungungo, this system saw water flowing from local taps for the first time ever, in 1992, providing more than 40L of water per person, per day. Within four days of completion of a fog collection project in Tshanowa Juniour Primary School in Limpopo, school children and members of the local community were drinking water collected by the fog. Could this provide hope to dry areas of Makueni and Machakos where there is always fog in the mornings?

Nairobi is a scarce water city - like a host of others in Africa including Addis Ababa, Dakar and Lusaka. Across the continent, there are women and children who walk all day every day to collect a jerry can of water.

"It's time we were aware that water is a finite commodity and that we are water scarce, which calls for greater prudence in the way we manage and use it," Opines Martha Karua, former Water Resources Minister (Kenya).

According to government statistics, Kenya's per capita water supply is expected to fall from 700 cubic metres now to around 500 by 2010.

In the long term, water scarcity has a negative affect on the economy. It puts off foreign investors, caps agriculture and manufacturing production and hampers the creation of jobs. As Kenyans and Africans by extension fit in an oft repeated church recital: As it was in the beginning, so it is now, and will be forever, Amen, may drought quickly arouse us from our slumber of a thousand minor cares at the expense of major cares!